This is a bit misleading, IIUC. "Content creator" in this case means the nominal copyright-holder, which often means someone simply claiming copyright, in pract

This is a bit misleading, IIUC. "Content creator" in this case means the nominal copyright-holder, which often means someone simply claiming copyright, in practice, and not necessarily the uploader ("Fair Use" be damned). The person who uploaded the video might have fully intended there to be no ads run during playback, but has little say in the matter if someone comes along and claims that their content is used in the video.